Liquid level



"Apr'il25p1944. A G MRYLSKY 2,347,218

LIQUID LEVEL F11-ed sept. s. 1942 lllllllllbI IN VEN TOR.

Patented Apr.25, 1944 LIQUID LEVEL Gregory V. Rylsky, New York, N. Y.,assignorlto BendixAviation Corporation, Bendix, N. J., a corporation ofDelaware Applicaiicn scpicmbcr 3, 1942, sci-icl Nc. 457,215 Y s anims.(o1. 33 212) of a bubble. and more particularly to means for forming andadjusting the size of a bubble.

It is well known that in precision instruments of the above type inwhich a sealed bubble vessel is used, the size of the bubble varies dueto expansion and contraction of the liquid in the vessel due totemperature change. Y

Devices for adjusting the size bubbles within bubble vessels have beenprovided, heretofore, which comprise diaphragms or iiexible members oflike nature. These devices, because they were subject to the fulladjustment force necessary to form and adjust the size of a bubble,would rupture prematurely and thus destroy the necessary seal requiredfor proper operation.

An object of the present invention, therefore, is to provide a bubblevessel with novel and durable means for forming and adjusting `the sizeof a bubble within the vessel.

Another object of the invention is to provide novel bubble formingandadjusting meansfor a bubble vessel comprising mainly, a cylinder andpiston arrangement forY forcing liquid into and out of the bubblechamber.

A further object of the invention is to provide novel bubble forming andadjusting means for a bubble vessel comprising a cylinder and pistonarrangement together with a resilient member interconnecting the pistonand cylinder to dene a variable volume reservoir communicating with j Inthe drawing wherein like reference characy ters refer to like partsthroughout the several views,

Figure 1 is a vertical longitudinal section taken through one form ofliquid level embodying the present invention;`

Figure 2 is a `view similar to that of Figure 1,

lllustrating'a second embodiment ofthe presenta invention; and,

Figure 3 is-a view similar to the foregoing views, illustrating'afurther embodiment of the invention. v Referring nowto the drawing, andlmore particularly to Figure 1 thereof, the liquid; level, as shown,oomprisesa bubble chamber I0 formed by a cylindrical vessel II, a toplens -IZYand a bottom lens I3, together with retaining rings I4 and I5for urging the lenses intov contact with suitable abutments formed inthe cylindrical vessel. If desired, conventional sealing rings may beprovided between lenses I2 and I3 and the vessel I I to provide anefiicient seal for the liquid level.

The novel means of the invention Y are now provided for forming andadjusting the size of a bubble I6 Within the bubble chamber and, to thisend, the bubblechamber is connected by means of a passage Il with acylinder I8,'whch is formed integrally with vessel II or otherwisesuitably secured thereto. The outer periphery of cylinder I8 is threadedfor receiving a cupshaped member or housing I9. 'The inner periphery ofthe cylinder Iis highly polished, and receives for reciprocal movementtherein a piston 20.

Piston 20 is rigidly secured ,to a threaded rodV 2i which, in turn, isadaptedfor rotation in one direction or another by means of a suitableadjusting knob 22 `mounted within an opening provided for that lpurposewithinhousing I9. The piston, furthermore, has a given desirable depthso as to provide for itself a slight guiding action within the cylinder.L

A flexible coverlor boot 23 preferably constructed of thin metal, whichmay be spun from sheet metal, is connected at one of its ends in anysuitable manner, such as, by soldering, for example, to cylinder I8 andat its other end to piston VZIJ.- Some clearance necessarily existsbetween piston 20 and cylinder I8` so that liquid fromv cylinder I8 willbe present as well within. the chamber dened by the iiexible boot. Thisconnection of the cylinder and piston with the exible boot provides avariable volume liquid reservoir efliciently sealed oi from the interiorof housing I9 and connected for communication with the bubble chamber.Furthermore, with the foregoing novel arrangement, it is obvious thatthe full adjustment force `exerted by knob 22 is expanded .upon piston20 so that the principal' able liquid. v11ncrdertogenerate a bubblewithin .nular chamber thebubble chamber, knob 22 is rotated Ito move`piston -2U.outwardly.re1ativeto cylinder I8 to releasethepressurewithin thebubble -chamberfand vthe cylinder. IThe.bubblewillfappear at'the `point where the'pressure' will havefa minimum value landthiswillbe:tothefright'of the piston, The

lA slightlymodiedform of the presentinvention is provided 'forperformingsubstantially the same purposefand operation as :abovedescribed and, as illustrated in fFigure'fZVcomprises a pis- .tonprovided withfap'iston;ring25;providing a seal betweenv the piston vandcylinder. The piston, itself, instead of thejgenerally flat operativesurfaceshownin Figure 1., 'is1providedwith an annular .chamber .26. Inorder to release the pressure within cylinder i8 lduring'movement of thepiston, the latter is provided with: a restricted oriceZI communicatingcylinder I8 through an- 28 with the chamber formed by flexible boot 23.Except for'thefforegoing minor changes, themethod of producing a bubbleand adjusting its size within the bubblefcham'ber is the same as .thatset forth inconnection with the structure :ofiFigure 1.

. Figure f3 illustrates -a still further embodiment of the vinvention#wherein f the .structure shown is substantially' the same as that ofthe preceding gures exceptfthat in place of thefiexible -boot23forjoining the pistonfwith the cylinder, alexible cover-128 isprovidedwhich mayhave oneor more folds :the 'nature/.of .a isylphon. Theoperation of "this structure, .as will be apparent, is similar .to thatdescribed in ,connection with Figures`1 and `2.

As previously' pointed out, :with the bubble chamber, cylinder .and bootYor Sylphon completely `iilled with liquid, a bubble will appear.upon-outward .movement oflpiston 120 at the .point of the liquidWherethejpressure 'is of aminimum value. This uneven distribution of:pressure will existwhile the Vpiston-is kin motion and the liquid is ina dynamicstate.

The distribution of ,pressure during outward pistonmotion is sucht-hatWithin the chamber formed `by 'the 'flexible .boot 'onsylphon member thepressure-willincrease andthe amount of Aincrease will .depend upon theleakage between'the piston and Cylinder of 4Figures .1 and 3 or theIoriiice A2`I .of Figure 2. The pressure within the bubble chamber willdecrease and the-change will depend upon the clearance 'of-*passage|-'l. The greatest :pressure change occurs within cylinder I8 to theright Yof lpiston'220 ata point furthest removed from passage l1 and the'leakage clearance between .the kcylinder :and :the chamber formedbytheflexiblei cover. lSuch apoint is'one locatedsubstantiallyfat thecorner of vthe piston face. Hence, a bubble will "appear Within `thecylinder .at vthe point-indicated and Vnowhere else. The chamber denedvby Vthe vflexible boot or the Sylphon member represents a thirdchamberwherein, .during aL dynamic stateof the system, the pressure change willbe of an opposite value tor that within the cylinder and the bubblechamber. ,A'bubble however,A will never be generated behind .the pistonbecause even Vthoughtheexisting bubble within'the bubble chamber isbeing compressed, the 4pressure within the boot vor said bubble chamber,a piston said cylinder and forming a vscope of the invention as will nowbe understood by those skilled in the art. For a definition of thelimits of the invention, reference will be had primarily to the appendedclaims.

I claim:

1. A liquid level comprising a bubble chamber, a reservoir defining acylinder one end oi which communicates with said bubble chamber, anactuating piston for said cylinder, and a flexible sealing memberinterconnecting said piston and the opposite vendof said cylinder andconstituting a part of said reservoir.

2. A liquid level comprising a bubble chamber. a reservoir dening acylinder one end of which communicates with ysaid bubble chamber, apiston lmounted for` movement within said cylinder, a

kjoining the opposite end of ysaid cylinder with said vpiston andconstitutingzfa part of said reservoir, and rotatable means forAactuating. said piston.

4. A liquid level comprising ya bubble chamber, a lreservoir deiiningafcylinder one kend of which communicates with said bubble chamber, apiston mounted for movement -within said cylinder, a sealing ringcarried bysaid piston for cooperation with said cylinder, a resilientmemberconnecting said piston with the opposite end of said cylinder andconstituting a part lof 4said reservoir, and means providingl.restricted Ycommunication between sai-d cylinder'-andfsaid.'resilientmemben 5. vA liquid level `comprising a bubblechamber, a housing, a cylinder Within said housing and having one' endthereof in communication with mounted for movement within said cylinder,a ilexible sealing cover connecting said piston with the opposite end ofpart of said reservoir whereby said cylinder forms a reservoir closedon' from saidhousing and communicating with said 'bubble chamber, andmeans for actuating said piston.

6. An adjustable liquid level comprising a bubble chamber, a reservoirdening a cylinder kone end of which communicates with said bubblechamber, a liquid within said bubble chamber and said reservoir andforming a bubble within said bubble chamber, a piston mounted formovement Within said cylinder, a flexible sealing memmums 3 7. A liquidlevel comprising a bubble chamber, a reservoir dening a cylinder one endof which communicates with said bubble chamber, a piston mounted formovement within said cylinder, a flexible metal boot interconnectingsaid piston to the opposite end of said cylinder and forming a part ofsaid reservoir, and a rotatable knob for actuating said piston.

8. A liquid level comprising a bubble chamber,

a reservoir defining a cylinder one end of which communicates with saidbubble chamber, a, piston adapted for movement within said cylinder, aflexible Sylphon member connecting said piston with the opposite end ofsaid cylinder und formlng a part of said reservoir, and means foractuating said piston.

GREGORY V. RYLSKY.

